EYES OF CHRYSOCHLORIS HO'TTENTOTA AND C. ASIATICA. 3389 
SUMMARY OF STRUCTURE. 
1. The eye has sunk only into the dermis being surrounded 
by the hair-roots. 
2. The conjunctival sac is well developed and also gener- 
ally the lachrymal gland, the duct of which opens into the 
sac. From the sac, in most cases a cylindrical tube leads to 
the exterior. ‘his tube, however, from its direction and 
sometimes coiling, can be of no use as a path for light rays 
giving rise to vision. 
3. The eye muscles are quite absent. 
4, Sclerotic cornea and choroid are represented by the 
fibrous sclerochoroid. 
5. Lens and iris are very degenerate though recognisable. 
The vitreous humour is absent. 
6. The pigment layer of the retina is thick posteriorly, and 
absent anteriorly. 
7. The retinal layers are, in most cases, clearly distinguish- 
able, very little degeneration being apparent in the outer 
ones. ‘The layer of rods and cones is more or less distinct. 
8. The optic nerve is present in some, viz. the two adults 
and older immature form, though the ganglion cell layer is 
the most degenerate part of the retina. 
CoMPARISONS AND CONCLUSION. 
As regards the position of the eye, that of Chrysochloris, 
while not generally visible from the exterior, even after 
shaving off the hair, as it is in Scalops (Slonaker, p. 335) 
and Talpa (Kohl, 793, 795, p. 13), is still comparatively super- 
ficial in contrast to that of Rhineura (Higenmanp, 702, p. 535) 
and Notoryctes (Sweet, p. 549). 
The eye muscles are here absent, in contrast to most other 
burrowing forms, e.g. Scalops, Talpa (loc. cit.), Typhlops 
(loc. cit., and Kohl, 792, p. 124). The space between 
the conjunctival layers and between the eyelids is repre- 
